René Descartes, often nicknamed the "father of philosophy", was an inspired 17th-century philosopher, mathematician and scientist who pioneered modern philosophy and is perhaps best known for his “Cartesian Skepticism”, as a result of which he established a “fundamental element of Western philosophy”: “Cogito, ergo, sum. I think, therefore I am.” Descartes doubted the world and the reality that surrounded him and so, in a thought experiment, he hypothesized the existence of an evil demon, or "genius malignus" (evil genius), who deceived everyone by keeping them trapped in an illusory world. To evaluate the veracity of his reality, and being a "fierce rationalist", he renounced all his beliefs and began to critically examine each one to arrive at an authentic truth, and use it as a basis to deduce his ideas. return to a verifiable belief system. Descartes' ideas influenced the environment. To this extent, therefore, he relied mainly on the introspection of his own thoughts and ideas and rejected all sensory information because it was relative and therefore misleading or incorrect. Descartes explained that complex problems could be solved by breaking them down into smaller fragments, and he applied this “incisive” concept in his method of doubts. This methodology can be described using the analogy of a “barrel of apples”. To remove and discard the rotten apples in a barrel full of them, you must first remove all the apples, before separating the good ones individually and placing them back in the barrel. Similarly, Descartes gave up all his beliefs and examined them one by one, in order to discard all prejudices and find the correct beliefs before accepting them.